All of Google's free services only require you to have one log in and that is your Google Account log in.
You want to create one so that you have one universal log in to your Google Adwords, Google Analytics and other Google Products that you may use.
Follow these simple steps to create your Google Account:
- Go to https://www.google.com/accounts/NewAccount
- You can enter in your current email address and make that into your Google Account without having to create a gmail account.
- After you have entered your information and click on "I accept, Create my account" you will get a notification email from Google to verify your information.